The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 30, 2008
Filed:
Nov. 23, 2005
Tomoko Sugimura, Kobe, JP;
Koichi Sakamoto, Kobe, JP;
Atsuhiko Yoshida, Kobe, JP;
Sumie Suda, Kobe, JP;
Tomoko Sugimura, Kobe, JP;
Koichi Sakamoto, Kobe, JP;
Atsuhiko Yoshida, Kobe, JP;
Sumie Suda, Kobe, JP;
Kobe Steel, Ltd., Kobe-shi, JP;
Abstract
Disclosed herein is an ultra clean spring steel which contains inclusions easily elongated and broken into fine particles by hot rolling and which is easily adaptive to cold rolling and yields springs excelling in fatigue characteristics. The spring steel is characterized in that the wire contains oxide inclusions with a sulfur concentration no more than 10 mass % such that no less than 70% (in terms of numbers) of such inclusions, which exist in the outer layer outside one quarter of the diameter of the wire and have a width no smaller than 3 μm, satisfies the formula (1) below,CaO+AlO+SiO+MnO+MgO>80 (mass %) .   (1)